Presence of fluticasone propionate on human nasal mucosal surface and in human nasal tissue over a period of 24 h after intranasal application

Drug Release and Pharmacokinetic Evaluation of Novel Implantable Mometasone Furoate Matrices in Rabbit Maxillary Sinuses

BACKGROUND

Intranasal corticosteroid sprays (INCSs) used to treat chronic rhinosinusitis are suboptimal due to limited penetration into the middle meatus, rapid clearance, and poor patient compliance. A bioresorbable drug matrix, developed with the XTreo^TM drug delivery platform, may overcome the limitations of INCS by providing continuous dosing over several months.

OBJECTIVE

To evaluate the in vitro drug release and in vivo pharmacokinetics of novel mometasone furoate (MF) matrices in a rabbit dorsal maxillary osteotomy model.

METHODS

XTreo^TM matrices were formulated to consistently elute MF for up to 6 months. Matrices were surgically placed bilaterally into the maxillary sinuses of New Zealand White (NZW) rabbits. Tissue and plasma MF concentrations were measured to assess the in vivo drug delivery. The in vivo and in vitro drug release kinetics of the matrices were quantified and compared to those of rabbits receiving daily Nasonex^® MF nasal sprays.

RESULTS

XTreo^TM matrices self-expanded upon deployment to conform to the irregular geometry of the maxillary sinus cavities in the NZW rabbits. Sustained release of MF was demonstrated in vitro and in vivo for 2 MF matrices of distinct release durations and an in vitro-in vivo correlation was established. Therapeutic levels of MF in local tissues were measured throughout the intended dosing durations. In contrast to the variable peaks and troughs of daily nasal sprays, sustained dosing via a single administration of MF matrices was confirmed by quantifiable plasma MF concentrations over the intended dosing duration.

CONCLUSION

The XTreo^TM MF matrices provided targeted and efficient dosing to local sinus tissues that was superior to INCS. Sustained drug release was confirmed both in vitro and in vivo. The novel XTreo^TM technology may provide precisely tuned, long-lasting drug delivery to sinus tissues with a single treatment.

Biocompatibility and Pharmacokinetics of Fluticasone-Eluting Sinus Implant in a Rabbit Model

Background

A novel, bioabsorbable, fibrinogen-based implant has been developed as a mucosal dressing after endoscopic sinus surgery (ESS). This implant can be formulated with fluticasone propionate (TP) for local elution of corticosteroid to reduce postoperative inflammation and promote mucosal healing.

Objective

This study investigated the biocompatibility and pharmacokinetics of the implant in a rabbit model.

Methods

Implants with and without TP were placed on both intact and demucosalized maxillary sinuses of 33 New Zealand White rabbits. Sinuses with either intact or denuded bone without implants acted as controls. Histopathologic assessments were carried out at 5, 15, and 28 days. Concentrations of TP in the maxillary sinus mucosa, nasal cavity mucosa, and plasma were measured for up to 44 days.

Results

Implants placed on intact mucosa or denuded bone were grossly integrated within 15 days. Minimal foreign body reaction was seen with negligible differences for inflammation, fibrosis, or bone remodeling among controls, sinuses with the implant, or sinuses with the implant plus TP, at all time points. All samples also showed complete or near-complete percentage reepithelialization at 28 days, although the denuded bone controls demonstrated greater percentage reepithelialization at 5 days compared with denuded bone with the implant or implant plus TP (p <0.0001). The maxillary sinus mucosa demonstrated levels of TP of >140 ng/g up to 44 days. Plasma concentrations of TP were generally very low and were undetectable after day 7.

Conclusions

The implant and the implant plus TP seemed to be biocompatible in rabbits. The implant plus TP effectively eluted steroid locally over at least 44 days, with negligible plasma concentrations. Further studies are warranted regarding potential therapeutic applications in patients undergoing ESS for chronic rhinosinusitis.

Intranasal drug delivery: an efficient and non-invasive route for systemic administration: focus on opioids

Intranasal administration is a non-invasive route for drug delivery, which is widely used for the local treatment of rhinitis or nasal polyposis. Since drugs can be absorbed into the systemic circulation through the nasal mucosa, this route may also be used in a range of acute or chronic conditions requiring considerable systemic exposure. Indeed, it offers advantages such as ease of administration, rapid onset of action, and avoidance of first-pass metabolism, which consequently offers for example an interesting alternative to intravenous, subcutaneous, oral transmucosal, oral or rectal administration in the management of pain with opioids. Given these indisputable interests, fentanyl-containing formulations have been recently approved and marketed for the treatment of breakthrough cancer pain. This review will outline the relevant aspects of the therapeutic interest and limits of intranasal delivery of drugs, with a special focus on opioids, together with an in-depth discussion of the physiological characteristics of the nasal cavity as well as physicochemical properties (lipophilicity, molecular weight, ionisation) and pharmaceutical factors (absorption enhancers, devices for application) that should be considered for the development of nasal drugs.

The olfactory system is affected by steroid aerosol treatment in mice

Asthma needs continuous treatment often for years. In humans, some drugs are administered via aerosol, therefore they come in contact with both respiratory and olfactory mucosa. We explored the possibility that antiasthma corticosteroid treatment could influence the olfactory function by passage through the nose. A group of mice was exposed twice daily for 42 days to fluticasone propionate aerosol and was compared with a control group. Olfactory behavior, respiratory mechanics, histology, and immunoreactivity in the olfactory system were assessed. Fluticasone-treated mice were slower in retrieving a piece of hidden food, but both groups were similarly fast when the food was visible. When a clearly detectable odor was present in the environment, all mice behaved in a similar way. Respiratory mechanics indices were similar in all mice except for the viscose resistance, which was reduced in fluticasone-treated mice. Olfactory mucosa of fluticasone-treated mice was thicker than that of controls. Slight but consistent differences in staining were present for Olfactory Marker Protein but not for other proteins. A mild impairment of olfactory function is present in mice chronically treated with fluticasone aerosol, apparently accompanied by slight modifications of the olfactory receptor cells, and suggests monitoring of olfactory function modifications in long-term steroid users.

Dissolution in nasal fluid, retention and anti-inflammatory activity of fluticasone furoate in human nasal tissue ex vivo

BACKGROUND

Intranasal glucocorticoids represent the most effective pharmacologic treatment of allergic rhinitis. So far, no clinical data are available that compare fluticasone furoate (FF) with other intranasally applied glucocorticoids.

OBJECTIVE

Because the pharmacokinetic behaviour of drugs governs their presence at the therapeutic target site we analysed selected in vitro properties of FF in comparison with triamcinolone acetonide (TCA), budesonide (Bud), fluticasone propionate (FP) and mometasone furoate (MF). Additionally, we determined the anti-inflammatory activity of the glucocorticoid fraction residing in human nasal tissue samples after washing.

METHODS

We analysed the solubility of the compounds in artificial human nasal fluid and the retention in human nasal tissue as well as typical spray volumes of commercially available drug preparations. As an anti-inflammatory measure, we evaluated the inhibition of IL-8 release from epithelial cells.

RESULTS

FF is delivered in the smallest application volume per spray. Despite the low aqueous solubility of glucocorticoids, a fraction of the compounds is already dissolved in the aqueous supernatants of drug preparations (Bud>TCA>FP>MF>FF). The dissolution of FP, MF and FF was significantly enhanced in artificial nasal fluid and FF displayed the most pronounced enhancement of solubility in the presence of proteins. Consistent with this result, the highest retention in nasal tissue was observed for FF, followed by FP>MF>Bud>TCA. After washing of the nasal tissue samples, all compounds inhibited IL-8 release, with FF displaying the highest activity.

CONCLUSION

FF displayed beneficial properties for nasal application. Its low application volume per spray is a prerequisite for effective drug utilization by avoiding immediate loss by nose runoff or drip down the throat. Sustained dissolution and high tissue binding of FF should contribute towards an extended presence of compounds in nasal tissue as a basis for a prolonged pharmacologic activity.

Metabolism of ciclesonide in the upper and lower airways: review of available data

Ciclesonide is a novel corticosteroid (CS) for the treatment of asthma and allergic rhinitis. After administration, the parent compound ciclesonide is converted by intracellular airway esterases to its pharmacologically active metabolite desisobutyryl-ciclesonide (des-CIC). We investigated the in vitro activation of ciclesonide and further esterification of des-CIC to (mainly) des-CIC oleate in several human target organ test systems. Human precision-cut lung slices, alveolar type II epithelial cells (A549), normal bronchial epithelial cells (NHBE), and nasal epithelial cells (HNEC) were incubated with ciclesonide. Enzymes characterization and the determination of the reversibility of fatty acid esterification was investigated in HNEC and NHBE. Ciclesonide was taken up and converted to des-CIC in all cellular test systems. Intracellular concentrations of des-CIC were maintained for up to 24 h. Formation of des-CIC oleate increased over time in HNEC, A549 cells, and lung slices. The formed des-CIC fatty acid conjugates were reconverted to des-CIC. Increasing concentrations of carboxylesterase and cholinesterase inhibitors progressively reduced the formation of metabolites. The results derived from these studies demonstrate the activation of ciclesonide to des-CIC in the upper and lower airways. The reversible formation of des-CIC fatty acid conjugates may prolong the anti-inflammatory activity of des-CIC and may allow for once-daily dosing.

Uptake and metabolism of ciclesonide and retention of desisobutyryl-ciclesonide for up to 24 hours in rabbit nasal mucosa

Background

The nasal tissue uptake and metabolism of ciclesonide, a new-generation corticosteroid under investigation for treatment of allergic rhinitis, to its active metabolite, desisobutyryl-ciclesonide (des-CIC), was evaluated when administered to rabbits in a hypotonic versus an isotonic ciclesonide suspension. Nasal mucosa extracts from normal Japanese white rabbits were evaluated by high-performance liquid chromatography with tandem mass spectrometry detection after a single 143-μg dose of ciclesonide. Retention and formation of fatty acid conjugates of des-CIC were also measured in nasal mucosa extracts postadministration of a hypotonic ciclesonide suspension (143-μg single dose).

Results

Versus an isotonic suspension, the hypotonic suspension achieved higher concentrations of des-CIC (5.6-fold, 11.4-fold, and 13.4-fold; p < 0.05 for all) and ciclesonide (25.3-fold, 34.2-fold [p = not significant], and 16-fold [p < 0.05]) at 30, 120, and 240 min postadministration. Additionally, when administered via a hypotonic suspension, des-CIC was retained up to 24 h postadministration (45.46 pmol/g tissue). Highest concentration of major fatty acid ester conjugate, des-CIC-oleate, was detected in nasal mucosa at 8 h postadministration.

Conclusion

These data suggest that a hypotonic ciclesonide suspension provides higher intracellular concentrations of des-CIC up to 24 h, thereby providing a rationale for investigation of ciclesonide as a convenient once-daily nasal spray for treatment of allergic rhinitis.

Human receptor kinetics, tissue binding affinity, and stability of mometasone furoate

Mometasone furoate (MF) is a topically used glucocorticoid with high anti-inflammatory potency. In contrast to the wealth of data derived from clinical studies, information about the molecular pharmacology of the compound is lacking or contradictory. Thus, we elucidated the characteristics of receptor binding kinetics and receptor affinity in a bioassay. Metabolite formation was determined in human plasma and lung tissue as well as binding affinity to human lung tissue. Fast and extensive association of MF to the human glucocorticoid receptor was observed while the dissociation of the MF-receptor complex was faster compared to fluticasone propionate (FP). The relative receptor affinity of MF was calculated as 2200 (dexamethasone = 100, FP = 1800) and confirmed in a bioassay measuring the induction of the glucocorticoid regulated protein CD163 in human monocytes. In plasma and human lung tissue MF formed a 9,11-epoxy degradation product. The binding affinity of MF to human lung tissue was low compared to FP due to fast redistribution from tissue into plasma. These molecular pharmacological properties are in accordance with clinical data.

Techniques of intranasal steroid use

OBJECTIVE

The effectiveness of topical intranasal steroids (INS) sprays for the treatment of allergic and nonallergic rhinitis may be limited by lack of instruction in the optimal spray technique. To determine whether the technique used affects the efficacy and safety of the product, this review of evidence had the goal of identifying and establishing a preferred method of applying INS sprays.

STUDY DESIGN

A MEDLINE search of pertinent literature on 7 INS and 1 intranasal antihistamine spray preparations conducted with the use of appropriate search terms, yielded an initial 121 articles, 29 of which were identified as appropriate for review and grading for quality of evidence.

RESULTS

The analysis provided no definitive evidence regarding how best to instruct patients to use INS or antihistamine spray devices.

CONCLUSIONS

On the basis of a lack of clear evidence regarding instructions to maximize efficacy and safety of these drugs, the panel recommended a 7-step standard technique.

Comparisons of two Intranasal Corticosteroid Preparations in Treating Allergic Rhinitis

OBJECTIVES: Intranasal corticosteroid preparations can relieve symptoms of allergic rhinitis. Different aqueous corticosteroid forms have been developed for intranasal use. The objectives of this study were to compare efficacy and safety between fluticasone propionate and budesonide in the treatment for patients with allergic rhinitis.

METHODS: The study was conducted in a prospective and randomized manner; a total of 24 adult patients were enrolled. All patients received MAST allergen test at entry and again at 2 months after treatments. Fourteen patients received fluticasone propionate 200 μg once daily, and 10 patients received budesonide 200 μg twice daily. To investigate the efficacy of fluticasone propionate and budesonide, a subjective scoring system was designed to evaluate the symptom improvement of patients. Adverse events were recorded on a diary card then were analyzed. Mann-Whitney U test and Kruskal-Wallis 1-way analysis of variance were used for statistical analysis.

RESULTS: Analysis on patient-based symptom scores revealed that both fluticasone propionate and budesonide were equally efficacious in improving the symptoms of nasal blockage, sneezing, nasal itching, and watery rhinorrhea. There were no significant side effects reported for both groups during this follow-up period. However, analysis showed that the fluticasone propionate group demonstrated significantly greater improvement in some MAST allergen tests ( Candida, mite, house dust; P < 0.05).

CONCLUSION: Clinically, fluticasone propionate 200 μg once daily was efficacious as budesonide 200 μg twice daily in the relief of allergic rhinitis symptoms. However, fluticasone propionate can achieve greater immunologic improvement. Both preparations showed no evidence of short-term side effects.